Semiconductor memory chip module

Abstract

In a semiconductor memory chip module ( 2 ′) for a smart card, a nonvolatile memory chip (EEPROM) ( 4 ) and a volatile memory chip (SRAM) ( 6 ) are stacked and coupled directly by vertical chip interconnections ( 16 ). The rapid-access volatile memory permits fast execution of programs. Permanent and safe storage of data is effected by reloading the data to the nonvolatile memory. A chip ( 8 ) with decoder circuits can be contained in a further level. Likewise integrated into a chip is a buffer capacitor ( 20 ) which is constantly recharged to a constant supply voltage during operation.

What is claimed is:  
     
       1. A semiconductor memory chip module comprising: 
       a first memory chip of a first type;  
       a second memory chip a second type; and  
       an electric connection between the first and second memory chips;  
       wherein the memory chips are disposed one above the other in different levels and connected by vertical chip interconnections;  
       wherein memory cells of the first memory chip are firmly allocated to certain memory cells of the second memory chip, and the mutually allocated memory cells are directly interconnected electrically.  
     
     
       2. A chip module according to  claim 1 , wherein the first type corresponds to a nonvolatile memory, for example EEPROM, and the second type to a volatile memory, for example SRAM. 
     
     
       3. A chip module according to  claim 1 , wherein at least one further chip is provided in a further level. 
     
     
       4. A chip module according to  claim 3 , wherein the further chip contains decoder circuits for the memory chips. 
     
     
       5. A chip module according to  claim 1 , wherein an energy buffer is formed in at least one of the levels. 
     
     
       6. A chip module according to  claim 5 , wherein the energy buffer is formed as an integrated buffer capacitor. 
     
     
       7. A chip module according to  claim 1 , formed for a smart card. 
     
     
       8. A smart card having a semiconductor memory chip module according to  claim 1 .